Solving Sudoku : Multiple Lines

This is very similar to the Double Pairs Test, but is a little harder to spot. It works in the same way, but the candidates that occupy the lines could be spread across two of the blocks, and there could be several candidates in each line.

Look at these two 3×3 blocks, and see where the candidates for 5 are.

We’ll highlight those to make it easier to see – and you can see that the 5s are only in the first two columns.

This means that columns 1 and 2 are already taken for candidates for 5, leaving the middle box with only column 3 for its 5s.

That doesn’t allow us to place a value straight away, but at least we can remove the candidates for 5 from column 1 in the middle box.

This will help us later on in the puzzle!

This technique is a little bit harder to spot because there will be more than just two pairs, but will still help you make progress!